Various hand-held articles are manufactured from smooth hard materials which are inexpensive and amenable to standard manufacturing processes. In order to increase comfort during gripping of the hand-held article and/or to decrease possible slippage because of the smoothness of the material, various grip elements have been designed for placement on the gripping portion of the hand-held article. Because such grip elements are provided to address different problems or consumer needs, a variety of different grip elements with different properties are available.
For instance, for purposes of increased comfort to consumers who grip a hand-held article very tightly, grip elements of soft foam are provided to permit ready deformation of the grip element and resulting enhanced comfort during gripping thereof. Other types of grip elements with low durometers (hardnesses) are known, such as on the Dr. Grip® writing instrument manufactured by Pilot® Corporation of America, of Trumbull Connecticut, and the PhD™ writing instrument manufactured by Sanford, of Bellwood, Ill. However, to permit ready handling of known soft grip elements during manufacture and to facilitate assembly on the hand-held article, such soft grip elements require more material than is really necessary to achieve the desired enhanced comfort, thus increasing size or bulk as well as material costs. Moreover, insertion of a thick-walled grip element over the gripping section of a hand-held article results in a hand-held article significantly bulkier than would be the case without such grip element.
However, thin-walled tubular elements formed from very soft materials are difficult to handle for various reasons. For instance, the thin wall easily collapses on itself, requiring additional supporting and manipulating devices to permit insertion over a hand-held article. If the tubular element is transported in bulk, such as in a vibrating bowl, then the plurality of tubular elements collapse in transit, requiring manipulation to recreate their tubular configuration. Moreover, if the material is so soft that it has a high coefficient of friction, the collapsed walls may stick to each other to a certain degree, further complicating the handling of the tubular element.
In addition, if a grip element is designed to reduce slippage, such characteristic may backfire by interfering with ready sliding over the exterior of a hand-held article into the desired position on the article. A thin-walled grip element may stick to itself and wrinkle during insertion, further impeding insertion over the hand-held article.
Formation of the grip element directly on the gripping section of the hand-held article is one solution to the above-described problem of mounting a separately formed soft grip element onto a hand-held article. However, such solution has its drawbacks as well. If a molding process, such as a two-shot injection molding process, is used then the grip element is molded over a substrate which is typically the hand-held article itself. Because the hand-held article typically has a unique shape, the requisite mold complexity for such molding is relatively high, with accompanying high costs. The resulting mold process would likewise be expensive in order to control the high tolerances and critical features necessary to create a substrate with the desired features. For example, if the grip element is to be provided on a writing instrument, then the substrate is a writing instrument body which may have particular features requiring a complex, and thus expensive, mold. Moreover, if the substrate is the entire hand-held article, then only a limited number of mold cavities can be used per cycle for a given mold or press size.
Thus, it would be desirable to form a grip element from a material soft enough to provide the desired enhanced comfort while configuring the grip element to be readily assembled over the gripping section of the hand-held article.